Potentialy dumb question here, is there any benefit to using btrfs on a non system disk? I'm fairly ignorant on file systems, asfaik btrfs largest benefit is snapshotting, not sure of anyothers.
I usually just stick to the standard file system to any OS.
So for Linux that would be ext4.
For external drives i use either FAT32 (the ol' reliable) or exFAT (the fastest for dealing with large files when you set the max allocation unit size AKA 32MB).